Sealing rings according to the invention are particularly used as rotary shaft seals to seal a shaft against a shaft guide, which can also constitute a housing, or as piston rings.
Both the sealing ring and the groove receiving it mostly display a rectangular cross-section in the fields of application mentioned. In this context, one of the groove flanks serves to support the sealing ring and is a sealing surface at the same time. In various fields of application, sealing against the component to be sealed, with which the sealing surface of the sealing ring can be brought into contact, is accomplished by external pretensioning of the sealing ring, or by pressurization of the sealing ring by the respective fluid medium, by which the sealing ring is pressed against the supporting groove and the component to be sealed.
The incorporation of rectangular groove cross-sections in the respective component is, however, relatively complex on the one hand, since it entails notch effects, which are to be avoided for many applications, if at all possible. Reducing the notch effects by means of suitable groove geometries is complex and, at the same time, either reduces the wall thickness of the sealing element, and thus its sealing effect, or results in deeper grooves. To achieve sufficient tightness, it is often even necessary to elaborately machine the groove flanks by grinding or other work steps. In the case of sealing rings with a rectangular cross-section, and thus corresponding grooves in the respective component, one particular disadvantage is that, owing to the respective available space, the sealing rings can often not be provided with the necessary heights or widths that would be required for sufficient tightness. This is particularly the case if the sealing rings are supportively, or also essentially exclusively, pressed against the sealing surfaces by the pressure of the fluid medium, since adequately dimensioned pressurizing surfaces on the sealing ring can then often not be provided to a sufficient extent owing to the prevailing available space. If sealing against non-wear-resistant materials is required, alternative measures have to be taken, such as lining the housing bore with steel sleeves.
Moreover, with conventional sealing ring arrangements, the often confined space available causes problems as regards adapting the design of the sealing ring arrangement to different requirements or fields of application, since changing the groove depths is occasionally subject to narrow limits.